1. Field of the Invention
The present invention relates to a gas compressor assembled into an air-conditioning system for a vehicle or the like, and more particularly to a gas compressor in which it is possible to reduce a cost for the overall compressor without deteriorating its oil component separating function that is needed for the compressor, and to keep the oil component separating function constant for a long period of time.
In order to attain he above-described problems, a first object of the present invention is to provide a gas compressor that is suitable for reducing the overall manufacturing cost while attaining a reduction in the number of assembling steps and the parts relating to the oil separator. A second object of the present invention is to provide a gas compressor provided with an oil separator that is high in reliability to make it possible to keep a constant oil separation function that is needed for the compressor for a long period of time.
2. Description of the Related Art
In this kind of a conventional gas compressor, as shown in, for example, FIG. 11, a cylinder 2 having a substantially oval-shaped inner circumference is provided within a compressor case 1 and side blocks 3 and 4 are mounted at both end faces of the cylinder 2.
In order to achieve the above-mentioned objects according to the present invention, a gas compressor comprises a cylinder disposed in a compressor case, side blocks mounted on both end faces of the cylinder, a cylinder discharge port for discharging high pressure cooling medium gas which contains lubricant oil compressed in a compression chamber within the cylinder to a first discharge chamber that is an outside space of the cylinder, a second discharge chamber provided between an inner sealed end of the compressor and one of the side blocks, and an oil separator for separating lubricant oil component contained in the high pressure cooling medium gas to be introduced from the first discharge chamber to the second discharge chamber side. The oil separator is formed of a discharge pipe integral with one of the blocks and has an opening at one end to the first discharge chamber side with the other end opened toward an inner wall of the compressor case.
A rotor 7 is laterally provided inside the cylinder 2. The rotor 7 is supported rotatably through bearings 9 of the side blocks 3 and 4 and a rotor shaft 8 extending along the axis thereof. Also, as shown in FIG. 12, a plurality of slit-like vane grooves 11 are formed radially on the outer circumferential surface side of the rotor 7. Vanes 12 are mounted on these vane grooves 11 one by one. The vanes 12 are provided to be retractable and projectable from the outer circumferential surface of the rotor 7 toward the inner wall of the cylinder 2.
The interior of the cylinder 2 is partitioned into a plurality of small chambers by both surfaces at a tip end of each vane 12, outer circumferential surface of the rotor 7, inner surfaces of the side blocks 3 and 4 and the inner wall of the cylinder 2. The small chamber thus partitioned is a compression chamber 13. Such a compression chamber 13 within the cylinder 2 is rotated in a direction indicated by an arrow a in FIG. 12 to repeats the change in volume.
When the volume of the compression chamber 13 is changed, upon the increase of the volumes a low pressure cooling medium gas within the suction chamber 6 is sucked into the compression chamber 13 through suction inlets 15 of the side blocks 3 and 4 and suction passages 14 such as the cylinder 2. Then, when the volume of the compression chamber 13 is started to be reduced, the cooling medium gas of the compression chamber 13 is started to be compressed by the reduction in volume. Thereafter when the volume of the compression chamber 13 is close to the minimum level, a reed valve 17 of a cylinder discharge hole 16 provided at the oval short diameter portion of the cylinder is opened. Thus, the high pressure cooling medium gas within a compression chamber 10 is discharged to a first discharge chamber 18 of the outer space of the cylinder 1 from the cylinder discharge port 16 and further introduced through a gas passage 19 and an oil separator 20 to the side of the second discharge in chamber 5. In this case, lubricant is contained in the form of mist in the high pressure cooling medium gas discharged to the first discharge chamber 18. The lubricant oil component is separated by the collision with the oil separating filter 21 composed of metal mesh or the like for the oil separator 20.
Note that also as shown in FIG. 13, the lubricant oil component thus separated is dropped and reserved in an oil sump 22 of the bottom portion of the second discharge chamber 5. Also, the pressure of the high pressure cooling medium gas discharged into the second discharge chamber 5 is applied to the oil sump 22. The oil in the oil sump 22 to which such discharge pressure Pd is applied is fed to a back pressure chamber 25 of the bottom portion of the vane 12 passing through the side blocks 3 and 4, an oil hole 23 of the cylinder 1, the gap of the bearing 9 and a supply groove 24 formed in the surfaces, facing each other, of the side blocks 3 and 4 in this order.
However, in the above-described conventional gas compressor, as shown in FIG. 11, the side block 3 and the oil separator 20 are formed as discrete parts in view of the relationship of the structure in which the gas passage 19 for introducing to the oil separator 20 side the high pressure cooling medium gas containing the lubricant is formed between the mounting alignment surfaces of the side block 3 and the oil separator 20. For this reason, not only may a large number of parts such as an oil separator fastening bolt 26 (see FIG. 13) for mounting the oil separator 20 to the side block 3, a seal member for the mounting portion or the like be required, but also the assembling step for assembling the oil separator 20 to the side block 3 in the compressor manufacturing line. Thus, there are many factors for increasing cost, resulting in increase in cost for the overall compressor.
Also, in the above-described conventional gas compressor, as shown in FIG. 13, the oil separator 20 is fixed to the side block 3 by oil separator fastening bolts 26. Accordingly, if there is a defect due to the loosening of the oil separator fastening bolts 26, for example, when the loosening of the oil separator bolts 26, the mounting alignment surfaces of the side block 3 and the oil separator 20 are opened to split the gas passage 19, the high pressure cooling medium gas before the oil separation leaks to the outside of the gas passage 19 from the crack to cause the reduction of the oil separation property or the like. That is, there is a problem in that it is difficult to keep the constant oil separation function for a long period time.
In order to attain the above-described problems, a first object of the present invention is to provide a gas compressor that is suitable for reducing cost for overall equipment while attaining the reduction of the numbers of assembling steps and the parts relating to the oil separator, and a second object thereof is to provide a gas compressor provided with an oil separator that is high in reliability to make it possible to keep a constant oil separation function that is needed for the compressor for a long period of time.
In order to achieve the above-mentioned objects according to the present invention, a gas compressor comprising a cylinder disposed in a compressor case, side blocks mounted on both end faces of the cylinder, a cylinder discharge port for discharging high pressure cooling medium gas which contains lubricant oil compressed in a compression chamber within the cylinder to a first discharge chamber that is an outside space of the cylinder, a second discharge chamber provided between an inner sealed end of the compressor and one of the side blocks, and an oil separator for separating lubricant oil component contained in the high pressure cooling medium gas to be introduced from the first discharge chamber to the second discharge chamber side. The oil separator is formed of a discharge pipe integral with the one of the blocks and having an opening at one end to the first discharge chamber side and the other end opened toward an inner wall of the compressor case.
According to the present invention, the gas compressor is characterized in that the discharge pipe forms a discharge route of high pressure cooling medium gas without any bypass immediately before the inner wall of the compressor case from the first discharge chamber.
According to the present invention, the gas compressor is characterized in that the discharge pipe is composed of a straight tube extending linearly toward the inner wall of the compressor case from the first discharge chamber.
According to the present invention, the gas compressor is characterized in that the discharge pipe is opened at one end to the first discharge chamber side and at the same time opened toward the inner wall of the compressor case at the closest position immediately after the first discharge chamber.
According to the present invention, the gas compressor is characterized in that the one of the side blocks and the discharge pipe are cast integrally with each other.
According to the present invention, the gas compressor is characterized in that a means for forming the one of the side blocks integrally with the discharge pipe is adapted to take a structure in which a pipe press-fit hole in communication with the first discharge chamber is provided on the one of the side blocks, and one end of the discharge pipe is press-fitted in the pipe press-fit hole.
According to the present invention, the gas compressor is characterized in that a means for forming the one of the side blocks integrally with the discharge pipe is adapted to take a structure in which a screw hole in communication with the first discharge chamber is provided in the one of the side blocks, a screw portion is formed in an outer circumferential surface at one end of the discharge pipe, and the screw portion and the screw hole are engaged with each other and fastened and fixed to each other.
According to the present invention, the gas compressor is characterized in that a distance from an opening end on the side of inner wall side of a compressor of the discharge pipe to an inner wall of the compressor satisfies the following equation (1):
(xcfx80D2/4)xe2x89xa6xcfx80DLxe2x80x83xe2x80x83equation (1) 
where L is the distance, and D is the inner diameter of the opening end of the inner wall of the compressor case of the discharge pipe.
According to the present invention, the gas compressor is characterized in that the ratio of opening areas satisfies the following equation (2):
xe2x80x83S1/S2xe2x89xa70.7xe2x80x83xe2x80x83equation (2)
Where S1 is the opening area of the opening end on the side of the inner wall of the compressor case of the discharge pipe and S2 is the opening area of the opening end on the side of the first discharge chamber of the discharge pipe.
According to the present invention, the high pressure cooling medium gas compressed in the compression chamber within the cylinder is discharged to the first discharge chamber in the outer space of the cylinder through the cylinder discharge port. The high pressure medium gas immediately after the discharge is collided against the inner wall of the compressor case through the discharge pipe while keeping a high flow rate. The lubricant oil component contained in the high pressure cooling medium gas is separated by this collision.